Not Thought Through
by ComPow
Summary: Pacifica Northwest meets her match in Mabel Pines, someone who is too dumb to be affected by any of her attempts to get back at her for embarrassing her in front of people twice now. However, it seems she has found a vulnerability in the seemingly untouchable Mabel. Her twin brother, Dipper Pines.
1. Chapter 1

**What's up guys? I'm not the type to write an author's note, but I felt the need to do one since there's not enough room in the summary.**

 **This story is kind of an AU in which Dipper and Mabel move to Gravity Falls and don't encounter anything weird during the summer. There will be some weirdness in the future, but that's not going to be the focus of the story. So that's that, I hope you like this story.**

 **Not Thought Through**

Pacifica Northwest has it all. Money, looks, popularity, and power.

One of her ancestors had even founded the town she was in, so there was never a time when she didn't get something that she wanted. Her parents always bought her anything she asked for and, on the rare occasion that what she wanted something that was not for sale – like to get even with someone – then just a couple of words with the right people would take care of it.

No one dared to get on her bad side, and she loved it.

But this time was different. _Very_ different.

Pacifica is sitting in her limo, face flushed and eyes blazing in fury as she tries desperately to wipe the stupid glitter off her favorite pair of boots but it just won't come off. There's no way her parents are letting the boots anywhere near the house, if they found so much as a speck of glitter on the carpet they would freak.

"Stupid Mabel," she says through gritter teeth. She really likes these boots, she doesn't want to throw them away. "Ugh!"

She gives up, throws the shoes aside, and plops down on her seat.

It's hopeless. No matter what she does, more and more specks of glitter seem to appear. It's a nuisance she just can't get rid of.

Just like _her_.

Bright in a very annoying way and no matter what she tries to get rid of her, the idiot appears again with that ugly metal smile of hers. It must be a new record for how long it's taken her to hate somebody, after all she was sure that Mabel had only just moved to Gravity Falls like three months ago, around the beginning of summer.

Pacifica had seen the sweater-loving freak a couple of times during the break, but she never thought that the pest would end up being a thorn at her side.

She crosses her arms and glares at nothing.

There are ways to take care of people like her – people she disliked – in school. Spreading rumors, getting some of the more rowdy girls to do something to her target, or even bribe their friends into not speaking to her again. It hadn't failed before, that's why everyone knew better than to mess with her, but this time it just would not work.

No matter what she did, Mabel always shrugged it off. Even her freakish friends turned away her money and threats.

She wouldn't normally be this worked up about ruining someone, but Mabel had not only publicly humiliated her by letting a pig loose and getting her covered in mud in front of the whole town once before, but today she had tripped on her stupid two feet and covered her favorite boots with glitter.

Pacifica can't let someone get away with something like that. Her pride won't allow it. Not when it can cause her to lose what she's worked hard to get.

"Why is nothing working?" Pacifica fumes and slaps the leather car seat. "There has to be some way to get back at her. I can't let her run around like nothing happened, that would be like accepting defeat."

She sighs because nothing is coming to mind, it was like Mabel was some sort of invincible smiling monster.

The sound of a commotion snaps her out of her thoughts, and she peeks out the car's tainted window to see a lanky guy being pushed to the ground by a much larger guy. A crowd forms almost instantly but she can still make out the fight(?) and can even hear some of the words.

"Last chance Dipper, give me the papers," the larger guy threatens.

Dipper holds a stack of papers to his chest. "No way. I'm done letting you copy my work. I got in trouble with the teacher because of you!"

"You asked for it!"

The boy raises his fist but is stopped by a rainbow blur who tackles his back and tips him over.

"Leave my brother alone butt-face!"

Pacifica looks at the commotion in interest. She recognized the voice instantly. The one that tackled the guy was none other than Mabel.

And just like that it hits her.

As she watches the guy storm off when a teacher comes out of school while Mabel runs over to Dipper, Pacifica realizes that Mabel _does_ have a weakness.

How did she not think about it before? Her twin brother! The dork who's always got his face buried in a book.

A smile spreads across her face.

Yes, this was going to work. Mabel might be able to brush things off easily, but her brother seems a lot more vulnerable.

* * *

Dipper tries not to freak out when the bell rings. He decided that today he will not let anyone take advantage of him, specially Tyler, who could easily pass off for a fifteen year old.

It was odd to have someone pick on him, no one really did in California. Then again, maybe it had something to do with the fact that he had not made one friend since coming to Gravity Falls – one friend his age anyway.

He's not like Mabel, who has this strange infectious personality that people just gravitate to. When she came home with two friends the day after they first moved to their new house, he wasn't the least bit surprised. She was like that, happy and friendly. Things he was not.

His mom would sometimes tell him to be more like his sister and go meet friends, but that's way easier said than done. There's not one person he has anything in common with in class, nor does he share any of their hobbies.

If it weren't for Soos and his great uncles Ford and Stan, he would have no one to talk to other than Mabel.

He's broken out of his thoughts when he notices that most of the class is gone by now.

"Let's get this over with..." Dipper mutters to himself before walking out of the classroom. As usual the halls are full of people and he's glad that he had the insight to go to his locker before his final class started. Maybe he looks stupid walking around with a stack of papers, but it saves him time in going to the bus and time is important if he wants to leave unnoticed.

As much as he hates to admit it, he stands no chance in a fight against Tyler. The guy is twice his size and is even on the football team. Dipper, on the other hand, knows that he has – as Grunkle Stan puts it – toothpicks for arms, so logical thinking tells him to avoid confrontation.

He's doing just that and it looks like it's paying off since he's already out the school's front door. A feeling of relief washes over him but it's gone as soon as he feels a tug on the back of his shirt.

"Hey _Dipper_."

Dipper gets loose and turns around to see the giant form of Tyler standing over him.

"Just when I was going to your locker, someone tells me you're leaving already," Tyler says with a glare. "You can't do that. Not until you let me copy today's homework."

Dipper frowns, hides his face under his hat, and turns to leave but is pushed forward so hard that he ends up tumbling several steps forward but manages to keep himself from falling.

"Last chance Dipper, give me the papers," Tyler threatens.

Dipper bites his lip and his voice cracks when he says, "No way. I'm done letting you copy my work. I got in trouble with the teacher because of you!"

He swears he sees a vein snap on Tyler's forehead.

"You asked for it!"

The much bigger guy raises his fist and Dipper closes his eyes in anticipation but then he hears a familiar voice scream over the inaudible voices of the crowd that had gathered around them.

"Leave my brother alone butt-face!"

"M-Mabel?!"

Tyler staggers forward from Mabel's tackle and can't do nothing as she sits on his back and pulls on his hair.

Finally Mabel let's go and Tyler looks furious but thankfully a teacher walks out before things get out of control, probably hearing all the screaming, and Tyler is forced to leave.

"You okay Dipper?" Mabel runs to his side and asks.

"Yeah, I'm okay." He organizes the papers he was holding and sighs in relief. "Thank you for that."

Mabel laughs and slings an arm around his shoulders, "Hey, nobody messes with my brobro!"

He can't help but laugh and let her lead them to the bus.

He might not have friends his age, but if Mabel was at his side then he was sure everything would be okay.


	2. Chapter 2

**Not Thought Through**

Pacifica drums her fingers on the mahogany desk in her room. She's deep in thought, thinking about what she was going to do.

After three days of discreetly observing Dipper, she found out a lot of important things about him.

Firstly, it turns out that they actually have three classes together, all of which are advanced classes of course. As a Northwest it's expected of her to excel in school so, even though none of her friends share her classes, she has to sit in a room full of nerds. None of them try to get along with her, probably too intimidated, and she's grateful for that.

Secondly, Dipper is a loner in school and only ever talks to his sister and her friends. This can be good or bad depending on what she plans to do. It would be good if she asked someone to beat him up since he's alone a lot of times, but she doesn't think she's going to do that. Bruises heal way too quickly for her liking and she wants to set an example to Mabel. To show that she's not going to take her crap lying down.

Dipper being a loner also puts a damper on any plans she had to make his friends turn his back on him, or having people ignore him. He's already alone all the time so people ignoring him will be like white noise to him.

"Ugh," Pacifica supports her face on her hands and sighs.

This was just like with Mabel. She knows they're twins but this is ridiculous. The only difference between the two of them is that one is a girl and the other...

"That's it!" Pacifica brightens up and stands up. "Dipper is a boy."

Of course! He's a boy and there is a very easy way to hurt boys.

She'll make him fall for her, maybe even start to _'date'_ him. Make him think that she actually likes him too, build trust between them, and then finally dump him in the most humiliating way possible. She would need an audience for that and – almost like a sign – there is a big dance coming up on Halloween. It's only two months away but that should be enough time to make the geek fall head over heels for her.

She already can't wait for Halloween but she has to calm herself. Thinking ahead was fine, but dwelling too much on it might cause her to be impatient. Approaching a loner like Dipper has to be done in a natural way. He'll obviously be suspicious if she randomly starts talking to him.

What she needs is to be patient and take her time. Sharing three classes with him makes this plan a lot easier and she's going to take advantage of that.

* * *

Pacifica can hardly concentrate on whatever the teacher is rambling about as she stares at Dipper who – as usual – sits alone while reading some old book.

She knew that it would be hard to talk to him but the last two classes they had together had not given her the chance since the teachers really loved to hear themselves class. This one looks to be no different.

Pacifica sighs and leans her face on her hand. She was hoping to talk to him today so that she can start her plan but it doesn't look like there's an opening today.

"This is very important so pay attention."

The teacher's voice snaps Pacifica out of he thoughts and she's forced to listen.

"We're going to have a project that will be worth twenty five percent of your grade."

Great, now she has to do some dumb stupid project.

"You guys will form teams of two and write a report on anything you want, so long as it is native to Gravity Falls. Can be a place, person, or object; just make sure to follow the instructions on how to make the report. Also, before you ask, you _can_ choose your own partner. Get your partner and then I'll give you a couple of sheets."

The class is loud and lively in an instant as students get up to form teams with their friends, and Pacifica can hardly believe her luck. She can't even keep herself from smiling at her fortune. This is perfect! Of course, she can't outright tell Dipper to be her partner which is great because he has his eyes glued on a book.

* * *

Dipper licks his lips in anticipation as he reads his mystery book. The detective protagonist was just about to confront the killer!

"Ms. Peterson says I have to pair up with you."

Dipper looks up from his book to see none other than Pacifica Northwest. He has heard all about her from Mabel, how she goes out of her way to mess with her and had even tried to turn Candy and Grenda against her.

He can hardly keep his disdain in check as he asks, "What do you want?"

Pacifica rolls her eyes, "I said that Ms. Peterson told me to partner up with you for the project. Were you not listening?"

"Project?" He repeats and looks around the room to see that a bunch of people had partnered up.

This was nothing new, he was usually the last to find a partner, but why Pacifica of all people? He doesn't want anything to do with someone that had it in for his sister.

"Yes, it's twenty five percent of our whole grade so you better take it seriously."

"Why should I help you?" Dipper asks with a frown, not liking the tone she was using on him.

"You're not helping _me_. We're being forced to work together, so I'm proposing to put aside our differences and work on this. I don't know about you, but I don't want a B in my report card."

To be honest neither does he. Not only would he disappoint his parents, but Great Uncle Ford – someone he admires – as well.

He sighs, "Fine."

"Good," Pacifica says in a pleased voice and hands him a piece of paper.

A project on whatever they wanted so long as it had something to do with Gravity Falls? He hates these. Not because they're a lot of work or anything, but because he can never think of what to research.

"We'll talk over the project after school. Meet me at the front entrance as soon as the final bell rings."

"Wait, what?" Dipper asks but she walks away with a smirk.

Great, now he _has_ to meet her.

He looks over the paper again and frowns when he realizes that the project isn't due until the very end of their first semester, meaning that he has to put up with her haughty attitude until the end of the year.

Dipper puts his head down on his desk, "Just perfect."

He stays like that for a few moments before the bell rings and the more impatient students run out. Dipper takes the book he'd been totally engrossed in and holds it under his arm along with a couple of notebooks, before he walks out of class. The halls are as busy as always but he somehow maneuvers through them while his mind in somewhere else entirely, troubled with the whole Pacifica thing.

He's never even traded two words with her before today, but he can already tell that she's just like Mabel described her. Snobby, bossy, and just plain mean. He's so not looking forward to the next couple of months.

"Hey Dipping Sauce, why the long face?" Mabel asks.

It isn't until he hears her voice that he realizes that his body automatically took him to his locker. Mabel actually looks a little bit worried and he can already tell that trying to keep the truth from her will not happen. She has a way of digging the truth out of him so well that he doesn't think he's ever managed to keep one secret from her.

"Just found out my class is having a big project due at the end of the year."

"Ah, boo! That's horrible!"

He tries not to roll his eyes at that, leave it to Mabel to think of a project as _'horrible,'_ though she's actually right this time.

"It's not so much the project, but who my partner is."

Mabel laughs, "What? Aw come on Dipper, no one can be that bad."

"What about Pacifica Northwest?"

Her smile drops instantly and she looks at him closely, "Are you serious?"

"Yup. My partner until the end of the year is going to be Pacifica."

"You have to be careful around her Dipper," Mabel grabs him by the cheeks and looks him straight in the eye with narrowed eyes, " _She's dangerous_."

"Okay, you're exaggerating," he pushes her away.

She laughs," Maybe a little, but she's actually pretty mean." Her eyes narrowed and she turns in the direction of his last class, "I should probably talk to her or something."

He grabs her shoulder before she can go anywhere. "No you're not. I don't need your help, I can handle this on my own."

Mabel seems unsure but sighs, "Okay, brobro. Just tell me if she tries anything."

Dipper frowns, he really likes his sister, but it really annoyed him when she treated him like a defenseless baby. Just like she's doing right now.

"Fine, fine. Now go to class before you're late again."

"Okay grumpy head, I'll see you later."

Dipper turns and begins to make his way to his next class. Unlike his last one, the teacher didn't let him read during class. It's the reason for why that's his favorite class. The teacher already knows that his grades are good so she pretty much let's him do whatever he wants as long as he doesn't disturb the class – not that he would anyway.

He sees Pacifica talking to a group of popular girls when he passes by her locker, and is reminded that he's going to be working with her for a while.

"Happy thoughts Dipper," he mutters to himself, already feeling the stress that was sure to come. "Happy thoughts."

* * *

If there is something that Pacifica hates, it's being made to wait.

She's standing in front of her limo, arms crossed and foot impatiently tapping on the sidewalk. School ended like ten minutes ago and the idiot – who is very lucky that she's letting him set his dirty commoner feet on her limo – still isn't coming.

A couple of kids look her way, probably curious, but she shuts them down with a glare that makes them dart their eyes and walk away.

It's not until two more minutes pass that the geek finally comes out of school, not looking at all bothered about being so late.

"Why did you make me wait?" Pacifica seethes.

"I had stuff to do," Dipper answered with a frown.

Uh oh, she can't make him angry. Even though he totally deserves it, she bites her tongue and takes in a calming breath. "Sorry, I was just worried because I have to attend my piano class after this."

"Oh..." Dipper trails off, actually looking a bit guilty. "Sorry about that."

Pacifica smiles – not able to contain how pleased she was that he felt guilty – and shakes her head dismissively, "It's okay. Get on."

"In the limo?"

"Well duh. We can't talk about our project properly here. I'll have my driver take us to a restaurant or something, we can get something to drink there."

Pacifica can see the hesitation on his face and decides to use his guilt against him and puts on an apologetic smile, "Sorry. I guess I was being selfish, but I wanted to get something to drink before I had to get to my class. It's okay if you don't want to come, we can talk here if you want."

The plan works like a charm and Dipper quickly answers, "No, it's okay. It's just that I've never been in a limo before."

"Good, come on," she leads him into her limo and leans over to talk to her driver, "Take us to a place that sells drinks nearby. Anywhere is fine."

"Of course, Miss Northwest."

Pacifica gets on her seat, making a mental note of how Dipper was putting a lot of distance between them despite sitting on the same long seat, and smiles to herself.

The first part of her plan was a success. She's made an excuse to spend a lot of time with Dipper and even has him in her limo. Step two, which is easily going to be the longest to complete, is next.

Make Dipper fall in love with her.


	3. Chapter 3

**Not Thought Through**

Dipper knows that he probably looks like a crazy person to the people walking in the busy hallways of school since he's resting his head against his locker, doing almost anything he can think of to stall his meeting with Pacifica.

After the final bell rang a few minutes ago, he dragged his steps, calmly put his book in his locker, organized some handouts, and even checked it over a couple of times. Of course, it's futile to delay the inevitable, but he just can't draw enough strength to tolerate being around someone like Pacifica Northwest.

Maybe he's just being melodramatic but he can't help feeling like this after hearing all about her from Mabel. Actually meeting Pacifica today only confirmed his impressions about her.

"Let's get this over with," Dipper resigns himself with a sigh, takes a deep breath, and walks out of school almost like he's about to face some monster.

He sees her almost instantly, her blond hair standing out between the sea of blurred faces rushing home.

"Why did you make me wait?" Pacifica seethes.

Dipper frowns at that. Only one second in and he was already hating this project, "I had stuff to do."

Maybe he could get the teacher to find him another partner.

"Sorry."

He looks at her in surprise, not expecting her to apologize for her bad attitude.

"I was just worried because I have to attend my piano class after this."

And now he feels like a jerk.

Of course someone like her probably has a bunch of things to do after school. He's read several stories where rich kids are forced into a bunch of different things by their parents and pressured into giving good results. There's no actual way he'll ever know if this was true for Pacifica but, while all that is expected of him when coming home is to do his homework and a couple of chores, she probably has her own crap to do.

"Oh..." He trails off. She might not get along with Mabel, but he's not spiteful enough to give her trouble when she's done nothing to him, yet anyway. "Sorry about that."

To his surprise, she smiles and shakes her head dismissively, "It's okay. Get on."

He's so thrown off that he dumbly points at the car, "In the limo?"

"Well duh. We can't talk about out project properly here. I'll have my driver take us to a restaurant or something, we can get something to drink there."

Oh no, he didn't sign up for this. He's willing to tolerate working together with her, but only if they do it in school.

"Sorry. I guess I was being selfish," Pacifica says with an apologetic smile, probably seeing that he was against it. "But I wanted to get something to drink before I had to get to my class. It's okay if you don't want to come, we can talk here if you want."

Again, he feels like a complete jerk. Pacifica probably wanted to talk to him in school but because he was late on purpose she was running late.

"No, it's okay. It's just that I've never been in a limo before."

"Good, come on."

He's relieved when she smiles and lead him into the limo, and follows her in.

The seats are actually pretty comfortable, the windows are tinted, and the inside is crazy spacious. Pacifica is talking to the driver about something while he looks around in – he hates to say it – awe.

Rich people have it good.

* * *

Pacifica is silent as she sits at an ugly stall in one of those restaurants for poor people - the ones where you could actually buy stuff from your car - and waits for the drink she ordered since she knows better than to buy anything from such a dirty looking place.

She glances to the other side of the small table, eyeing Dipper who was drumming his fingers and looking away. It doesn't sit well with her to see how much he dislikes being around her. Not only because it's only going to make him fall for her even harder, but because the loser should be honored that he's allowed to sit at the same table as her.

"Table 9, your drinks are ready!"

Dipper looks up, "That's us."

Wait. Wait! What?!

"They make you get your own drinks?" Pacifica is insanely thrown off by that. Did poor people restaurants treat their customers like trash? Well, if they thought they could do the same to her then they had another thing coming, she can buy this crappy place and everyone in it!

"Aren't you coming?" Dipper looks at her oddly and she's reminded of her mission.

Dipper has to fall in love with her, and in order for him to do that she has to get rid of any negative thought he has about her. If she lashes out at anyone here then she would just be confirming whatever it is he thinks of her.

So, she puts on what she hopes is a passable smile, and follows after him. She takes her drink – ew, it's in a carton cup – and glares at the teenage girl behind the register for making her do her work for her.

"Our first step should be to brainstorm on what we want to do the project on," Dipper says once they both take a seat. "I was thinking about doing something on the ecosystem."

Pacifica nods absently, her mind preoccupied with the thought that she did not want to drink from the gross carton cup. She asked for a water after seeing that they had nothing but soda and juices that a place like this clearly made with the highest amount of sugar possible.

"What do you think?" Dipper asks.

"Ecosystem is a good idea," she answers and takes a hesitant sip of her drink. "Are we going to have to look around the woods or something?"

"Yeah. We'll need to do fieldwork..." he mutters to himself as if thinking of something and then puts on a hopeful grin, "I can do it on my own if you want."

Pacifica fights the urge to frown. If he thought he could get rid of her so easily then he was even dumber than he looked.

"Of course not," she says with a friendly smile, "I'll come too. It wouldn't be fair to let you do all the work."

Dipper looks at her curiously, "Really?"

"Yeah," she answers and then grins, "Don't think I'm afraid of a little hiking. I go camping all the time on breaks."

Pacifica inwardly smirks when seeing Dipper's face shift from surprise to approval. Her plan is already working!

It doesn't matter how small, making his image of her change was the first step in her plan. She just has to continue to play the part of a friendly misunderstood girl and then bam! He'll be head over heels for her!

It's almost too easy.

* * *

"Thanks for the lift," Dipper says as he steps out of the limo.

After getting a general idea of what they wanted to do, Pacifica had offered to give him a ride home, which was good since his house was like half an hour away on foot.

"No problem," Pacifica says with a smile and looks out the window. "You know, since your house is pretty much in the woods, we should meet here one day to do our fieldwork."

"Sounds good."

"Okay, let's meet at lunch tomorrow so we can figure out a date," she pauses and waves, "See you later."

"Yeah," he answers with a wave he knows looks a lot more lame than he imagined.

Dipper grins as the limo drives off. Truth be told, he feels like a lot of the things he heard about Pacifica were wrong.

She did only have one sip of her drink. A small smile forms on his face when he thinks of how she pouted and grimaced cutely when seeing something greasy of dirty on the restaurant. It _was_ called Greasy's for a reason. He chuckles to himself and wonders on where they should go next-

Dipper clears his throat and pushes away those thoughts, not liking where that train of thought was going.

Pacifica **is** pretty snobbish, but he figures that it's probably because of her upbringing and she can't help it. Doesn't mean he has to like it, but he at least knows that she's not doing it to spite others or anything. Well, except for Mabel.

He frowns, remembering the feud between the two.

Pacifica might not be as bad as everyone made her out to be, but he's not about to become friends with her. He's just glad that she's not unreasonable and the project won't be as bad as he first thought.

Dipper nods to himself and goes inside his house. He's surprised to find Mabel sitting on the couch watching TV.

"Hey brobro, how'd it go?" Mabel asked impatiently.

"Have you been waiting for me?"

"Of course! I was worried about the whole Pacifica thing so spill already!"

Dipper chuckles, "Actually, she wasn't as bad as I thought."

Mabel raises her eyebrows in surprise, "Really? She didn't try anything? Didn't try to leave you stranded in the middle of the woods?"

"She didn't," he says with a roll of his eyes, wondering what movie gave her that idea. "In fact, I think this project might go well."

Mable frowns, "I dunno Dipper..."

"Relax, I'll be on my toes," he answers with a dismissive wave of his hand, "She may be acting friendly, but I won't let it cloud my judgment."

Mabel brings a hand to her mouth and gives him a worried look, "Are you sure you'll be okay?"

"I will," he answers, annoyed mostly at himself for making Mabel be so worried about him.

He walks up the stairs and heads to the restroom, he really wanted a shower after being in school all day.


End file.
